1. Field of the Invention
The present invention relates to a photographing (imaging) lens (lens barrel) in which a part of a plurality of optical elements, constituting a photographing optical system, retracts to a position deviating from the photographing optical axis of the photographing optical system when the photographing lens moves from an operating state to a non-operating (fully retracted) state.
2. Description of the Related Art
Miniaturization of lens barrels incorporated in optical devices such as cameras has been in increasing demand. Above all, further miniaturization of retractable photographing lenses, specifically the length thereof in a non-operating state, has been in strong demand. To meet such demands, the inventor of the present invention has proposed a retractable photographing lens disclosed in U.S. patent application Ser. No. 10/368342 in which an optical element of a photographing optical system is retracted to a position deviating from the photographing optical axis of the photographing optical system, and at the same time, the optical element (together with other optical elements of the photographing optical system) is retracted along the optical axis of the photographing optical system when the photographing lens is fully retracted.
In this retractable photographing lens which reduces the length thereof in a fully retracted state in such a manner, when the lens is fully retracted, a flexible PWB (printed wiring board) which extends from a shutter unit positioned in a lens barrel tends to sag easier than that provided in a conventional retractable photographing lens in which all of the optical elements thereof always remain on the optical axis of a photographing optical system. Accordingly, the retractable photographing lens disclosed in the aforementioned Patent Application is required to have a structure preventing the flexible PWB from interfering with internal elements of the retractable photographing lens. However, providing the retractable photographing lens with such a preventing structure independently of other elements of the retractable photographing lens generally increases the size of the photographing lens, which runs counter to miniaturization of the photographing lens and is also undesirable in terms of the production cost.